A number of satellites were passing through my field of view, and one happened to be of similar size and brightness to the star I was autoguiding on. Turns out, the satellite passed exactly (or near enough) over the autoguide star in such a fashion that PhD2 switched to tracking the satellite instead! It also happened that this satellite (well, actually a pair of them) were traveling slow enough that my CEM26 was able to keep up with it. Before switching to the satellite:
Aaand we’re now tracking one of them (cropped sub):
So a failed attempt at the Witch Head, but an interesting image nonetheless. I had to use ASTAP to register on each one of the satellites. It appears that they move a little bit relative to each other:Registered on the right satellite:
Registered on the left satellite:
Using Stellarium, they appear to be a pair of satellites in the Naval Ocean Surveillance System(NOSS), specifically NOSS 3-7 (A), international designation 2015-058A:
These apparently track sea-going ships by measuring the time-difference-of-arrival of radio transmissions from the ship to the pair (or sometimes trio) of satellites. Interestingly, another source says the actual nature of the satellite is classified, so it may have other uses than just tracking ships. And yet another source confirms they’re US military SIGINT satellites.
